US4816074A - Kaolinite aggregation using sodium silicate - Google Patents
Kaolinite aggregation using sodium silicate Download PDFInfo
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- US4816074A US4816074A US07/149,638 US14963888A US4816074A US 4816074 A US4816074 A US 4816074A US 14963888 A US14963888 A US 14963888A US 4816074 A US4816074 A US 4816074A
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- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H19/00—Coated paper; Coating material
- D21H19/36—Coatings with pigments
- D21H19/38—Coatings with pigments characterised by the pigments
- D21H19/40—Coatings with pigments characterised by the pigments siliceous, e.g. clays
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- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09C—TREATMENT OF INORGANIC MATERIALS, OTHER THAN FIBROUS FILLERS, TO ENHANCE THEIR PIGMENTING OR FILLING PROPERTIES ; PREPARATION OF CARBON BLACK ; PREPARATION OF INORGANIC MATERIALS WHICH ARE NO SINGLE CHEMICAL COMPOUNDS AND WHICH ARE MAINLY USED AS PIGMENTS OR FILLERS
- C09C1/00—Treatment of specific inorganic materials other than fibrous fillers; Preparation of carbon black
- C09C1/40—Compounds of aluminium
- C09C1/42—Clays
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- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/51—Particles with a specific particle size distribution
- C01P2004/52—Particles with a specific particle size distribution highly monodisperse size distribution
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- C01P2004/60—Particles characterised by their size
- C01P2004/61—Micrometer sized, i.e. from 1-100 micrometer
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- C01P2004/60—Particles characterised by their size
- C01P2004/62—Submicrometer sized, i.e. from 0.1-1 micrometer
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- C01P2004/80—Particles consisting of a mixture of two or more inorganic phases
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- C01P2006/00—Physical properties of inorganic compounds
- C01P2006/14—Pore volume
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- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2006/00—Physical properties of inorganic compounds
- C01P2006/19—Oil-absorption capacity, e.g. DBP values
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- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2006/00—Physical properties of inorganic compounds
- C01P2006/21—Attrition-index or crushing strength of granulates
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2006/00—Physical properties of inorganic compounds
- C01P2006/60—Optical properties, e.g. expressed in CIELAB-values
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
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- C01P2006/80—Compositional purity
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2006/00—Physical properties of inorganic compounds
- C01P2006/80—Compositional purity
- C01P2006/82—Compositional purity water content
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2006/00—Physical properties of inorganic compounds
- C01P2006/90—Other properties not specified above
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/31504—Composite [nonstructural laminate]
- Y10T428/31971—Of carbohydrate
- Y10T428/31993—Of paper
Definitions
- This invention relates generally to kaolin products, and more specifically relates to a structured kaolin pigment and methods of manufacture of same.
- the pigment is useful as a filler in paper products and enables preparation of paper coating formulations which yield resultant coated paper products of surprisingly enhanced properties.
- inorganic materials have long been known to be effective for many of the aforementioned purposes.
- titanium dioxide which can be incorporated into the paper in the form of anatase or of rutile. Titanium dioxide, however, is among the most expensive materials which are so useable. Thus despite the effectiveness of such material as a filler, its use is limited and satisfactory replacements have been much sought after.
- calcined kaolins are generally prepared by calcining a crude keolin which may have been initially subjected to prior beneficiation steps in order to remove certain impurities, e.g. for the purpose of improving brightness in the ultimate product.
- kaolin pigment particularly valuable for use as a filler
- properties which render a kaolin pigment particularly valuable for use as a filler are also well known. These include a low abrasion value, and high brightness and opacifying characteristics.
- the low abrasion is significant in order to assure that the resultant paper product may be manufactured and processed using conventional machinery without damaging same.
- the brightness and opacifying characteristics are important in producing an acceptable paper sheet, one which incorporates whiteness, high opacity, good printability, and light weight.
- the said parameter i.e. the scatterinag coefficient S of a given filler pigment, is a property well known and extensively utilized in the paper technology art, and has been the subject of numerous technical papers and the like. The early exposition of such measurements was made by Kubelka and Munk, and is reported in Z. Tech. Physik 12: 539 (1931). Further citations to the applicable measurement techniques and detailed definitions of the said scattering coefficient are set forth at numerous places in the patent and technical literature. Reference may usefully be had in this connection, e.g.
- the major portion of filler should be in the range of one micrometer.
- good light scatter cannot be achieved solely by using a kaolin having the said size characteristics: an essential further characteristic needed is that the kaolin be structured, i.e., formed from an assemblage of platelets interconnected or bonded to provide aggregates which include a network of the platelets.
- Aggregation can be of interest for additional reasons.
- many kaolin crude reserves are considerably finer than preferred by the paper industry; i.e., they have an unduly high proportion of particles with E.S.D.'s below 0.25 micrometers.
- Typical Cretaceous kaolins e.g., include 25 to 30% by weight of particles below 0.25 micrometers; and typical Tertiary kaolins can include 50 to 60% by weight of particles below 0.25 micrometers E.S.D. (equivalent spherical diameter).
- E.S.D. Equivalent spherical diameter
- a calcined kaolin pigment and a method for manufacture of same are disclosed.
- the said pigment consists of porous aggregates of kaolin platelets, and exhibits exceptionally high light scattering characteristics when incorporated as a filler in paper.
- This pigment which substantially corresponds to the commercially available product ALPHATEX® of the present assignee, E.C.C. America, Inc. (Atlanta, Ga.), is prepared by first blunging and dispersing an appropriate crude kaolin to form an aqueous dispersion of same.
- the blunged and dispersed aqueous slurry is subjected to a particle size separation from which there is recovered a slurry of the clay, which includes a very fine particle size; e.g. substantially all particles can be smaller than 1 micrometer E.S.D.
- the slurry is dried to produce a relatively moisture-free clay, which is then thoroughly pulverized to break up agglomerates.
- This material is then used as a feed to a calciner; such feed is calcined under carefully controlled conditions to typical temperatures of at least 900° C.
- the resulting product is cooled and pulverized to provide a pigment of the porous, high light scattering aggregates of kaolin platelets as described.
- Calcined kaolins have also found use in paper coating applications. Reference may be had to the paper by Hollingsworth, Jones, and Bonney, "The Effect of Calcined Clays on the Printability of Coated Rotogravure and Offset Printing Papers", TAPPI Proceedings, pages 9-16, 1983 Coating Conference, discussing the advantages of incorporating small quantities of calcined kaolins into conventional kaolin-based coating formulations. Brightness and opacity of the paper both increase with increased calcined kaolin content, as may be expected from a pigment with high light scatter, and in some formulations gloss may show a slight increase with increasing calcined kaolin content.
- Calcined kaolin products including those of the aforementioned ALPHATEX® type, are seen to be manufactured by relatively complex techniques involving a multiplicity of steps, including specifically a calcining step, plus various preparatory steps and post-calcining steps.
- the said product is relatively expensive to produce; and requires considerable investment in complex apparatus and the like--e.g. highly regulated calciners, etc.
- the conditions of preparation of these materials must be very carefully controlled in order to keep abrasion acceptably low in the calcined product. For example, the calcination operation tends per se to produce an abrasive product--in consequence of overheating--if great care is not taken to preclude such a result.
- uncalcined (sometimes referred to as "hydrous")kaolin both as paper fillers and for paper coating.
- uncalined material usually does not possess high light scattering qualities or good opacity, its usefulness, especially as a filler, is limited; and this (in addition to improving brightness) is indeed the particular advantage of calcined products of the ALPHATEX® type; i.e. by virtue of the aggregated structures of same, high light scattering properties are provided and good opacity.
- kaolinite is an aluminum hydroxide silicate of approximate composition Al 2 (OH) 4 Si 2 O 5 (which equates to the hydrated formula just cited).
- a composite silicate pigment prepared by a precipitation reaction employing an aqueous suspension of clay particles wherein spherical hydrous metal silicate particles are precipitated on the planar surfaces of clay particles having a platelet-type structure.
- the metal silicate pigment component is comprisedof the reaction product of a water soluble alkali metal silicate such as sodium silicate and a water soluble salt of a polyvalent metal, such as calcium chloride.
- (d) kaolinite is acting only as a support for spherical metal silicates.
- a structured kaolin pigment product which possesses improved light scattering characteristics, and hence is useful as an opacifier and light scattering filler for paper and paper products, and which may similarly be used in other paper manufacturing applications, including in the coating of same.
- a still further object of the invention is to provide a process for producing structured kaolin pigments as aforementioned, from a feed crude containinghigh percentages of extremely minute particles, e.g., less than 0.25 micrometers, to thereby convert a crude having limited value to the paper maker to one which can be readily and economically used in paper products.
- a yet further object of the invention is to provide a process as aforementiond, which enables low abrasion structured kaolin pigments to be produced from coarser process feeds than can normally be employed in calcination to produce a product of comparable low abrasion.
- a fine particle size kaolin feed is reacted in particulate form with a metal chloride, such as silicon tetrachloride, to form a chemically aggregated structured kaolin pigment.
- a metal chloride such as silicon tetrachloride
- Free moisture present in the particulate feed is sufficient to initiate at least a partial hydrolysis of the metal chloride or chlorides. If the moisturelevel is too high, however, it can diminish or impair the efficiency of the aggregation process. Thus in the instances where silicon and/or titanium chlorides are used, if the moisture level is too high relative to the metal chloride(s), then the hydrolysis products from the metal chlorides will predominantly precipitate as the metal oxide, i.e.
- the water to metal chloride molar ratio should be at least 0.23, and generally less than about 50, with from about 1 to 10 being a preferable molar ratio range.
- the lower limits of moisture are as indicated for silicon and titanium chloride; the upper limits in this case are not critical, except that when moisture level is greater than about 10% by weight of the feed, (corresponding to a water to metal chloride molar ratio of about 8.2), processing as a dry product becomes increasingly difficult, and can necessitate additional drying steps.
- the indicated steps are conducted under conditions such that the basic kaolinite crystalline structure (as determined by X-ray or electron diffraction) is not altered--i.e. the kaolinite is not rendered substantially amorphous, as occurs in conventional high temperature calcining as described for example in the aforementioned McConnell et al, Proctor, and Fanselow et al patents.
- ammonia is desirably added at addition levels of from about 8 to 16 pounds per ton of the feed mixture, the ammonia being added to the previously combined kaolin and metal chloride.
- ammonia can also form silicon-amine type polymers, which would further enhance and bond the particles. Enhancement of the said process is effected by the addition of an enhancing agent metal ion, believed to result in the formation of metal silicates, which function as binding agents, yielding stronger aggregates, and which also helps to neutralize the acidic by-products.
- the aggregation of fine kaolinite is caused to occur when treated with silicon tetrachloride.
- These micron size, bulky aggregates are used to improve the surface properties of coated paper and the opacity of filled paper.
- similar bulky, micron size aggregates of fine kaolinite mineral are achieved by treatment of the substantially dry substrate with aqueous silicate, followed by drying, pulverizing and exposure to an acidic gas.
- the time of treatment with the acidic gas suitably may vary from about 5 to about 15 minutes.
- the silicate is suitably an alkali metal, e.g., sodium silicate.
- the silicate solution should have a pH in the range of about 11 to about 14, preferably about 11.8.
- the amount of silicate based on the weight of the dry clay will be in the range of about 0.25 weight % to about 5.0 weight %.
- the amounts of this silicate solution will be in the range of about 0.62 weight % to about 12.5 weight % based on the weight of dry clay.
- the ratios of SiO 2 /Na 2 O of the sodium silicate can be varied in the range of 1.25 to 3.8; however, the preferred ratio is 1.25.
- the pH of the final product measured as a 20% slurry in water, will be in the range of about 2 to 6.5.
- an aggregation enhancing agent is selected from one or more members of the group consisting of the alkaline earth metal carbonates, chlorides or hydroxides, or lithium carbonate.
- the aggregation enhancing agent mixed with the kaolin preferably should provide from about 15 to 120 millimoles of alkaline earth metal or lithium ions per 100 parts by weigh of kaolin. This equates to from about 0.5 to 12% by weight kaolin of a particulate alkaline earth metal carbonate or hydroxide or lithium carbonate. Where the particularly preferred calcium carbonate or hydroxide are used, a more preferable addition range is from about 1.5 to 4% by weight of kaolin.
- the kaolin utilized as a feed for the invention can be the product of kaolin wet processing, wherein various conventional beneficiation steps known to kaolin wet processing are utilized; or in accordance with a further aspect of the invention, the kaolin can be the product of air classifying a kaolin crude, preferably to at least 88% less than two micrometers--depending upon the light scattering characteristics desired in the final product; except that where the product of the invention is to be used in coating formulations, the classification is preferably to at least 94% less than 2 micrometers.
- the aggregated products of the invention are found to have a pore volume which is higher than the feed kaolin used to form same, although lower than a calcined kaolin formed from the same feed.
- the pore void volumes of products of the present invention when prepared from fine particle size feeds are found to range from 0.35 to 0.5 cm 3 /g.
- the process of the invention serves to aggregate the very fine particles (i.e. the sub 0.25 micrometer particles) present in very fine feeds of the type heretofore discussed.
- These minute particles can indeed serve in the aggregates as bridges between larger (e.g. micrometer-sized) particles to which they are chemically bonded.
- one important advantage to the paper manufacturer is that the otherwise large percentages of troublesome extremely fine particles have been effectively removed as separate entities, but without the need for separation steps, together with the costly equipment required for such operations.
- the structured kaolin pigments of the invention comprise from about 5 to 60% and preferably from about 10 to 30% by weight of the total pigment component of the coating composition.
- the balance of the pigment can comprise any of the known coating pigments, such as coating grades of kaolins, calcium carbonate, titanium dioxide, plastic pigments, etc.
- the coating compositions, in addition to the pigment component, include conventional components, such as an adhesive binder, dispersants, and other known additives.
- the increase in gloss in the resultant coated papers is in part a function of the particle size characteristics of the feed kaolin used to prepare the structured kaolin pigments.
- the said feed should preferably be at least 94% less than 2 micrometers E.S.D.
- an aqueous sodium silicate solution is stable only above a pH of 10. Any attempt to lower the pH tends to bring about the formation and rapid crystallization of amorphous silica gel.
- This is a hard, sandy type gel, that is, hard and abrasive when dry and of extremely coarse particle size. Further, the gel is thick and heavy and difficult to pulverize by grinding. Consequently it is not a material having properties suitable in the preparation of fillers or coatings for paper.
- the silicate solution is extremely dilute, the pH can be lowered without precipitation/formation of silica gel (with, however, the disadvantages of requiring extensive drying and increasing the risk of high residue).
- monosilicic acid a precursor to silica gel.
- Three to five unit oligomers of this material can be considered to be a microsol, e.g., a submicron size silica sol. It is desirable to react such a microsol on the surface of the clay. The particles thereof have a high free energy so that they are very reactive towards the clay particles and to each other. Thus, if monosilic acid or its obligomer (no higher than five monomer units) is permitted to react with the hydroxyl groups of kaolinite, it would lead to aggregation. The aggregated product should behave similarly to that produced with silicon tetrachloride.
- the function of the acidic gas e.g., HCl
- HCl acidic gas
- bonding would occur only if there is formation of monosilicic acid.
- the formation of a microsol is caused by the reaction of surface deposited silicate on contact with the HCl gas.
- FIG. 1 shows the particle size distribution of an untreated kaolin, labeled “starting material” versus the kaolin treated in accordance with the invention, labeled “product”;
- FIG. 2 illustrates the paper gloss properties of the product of the invention when used in a paper coating
- FIG. 3 illustrates the printability advantage, print gloss properties of the product of the invention when used in a paper coating
- FIG. 4 shows the bulky openness of the coated sheet as measured by K and N ink absorption
- FIG. 5 illustrates the effect of feed moisture on the light scattering ability of the product of the present invention.
- FIG. 6 shows the effect of feed particle morphology on the light scattering ability of the product of the presnt invention.
- a blend of two fine North Eastern Georgia kaolin clays was refined according to conventional procedures.
- the refined clay was wet classified to 94% less than 2 micrometer E.S.D.
- the refined clay was flocculated with aluminum sulfate and sulfuric acid.
- the flocculated clay was filtered and redispersed using sodium polyacrylate and sodium hydroxide.
- the redispersed clay was spray dried by conventional technique and pulverized using a pulverizer, product of Mikropul Corporation.
- the pulverized clay was blended in a high shear Waring blender with 2.5% by weight, based on clay, of aqueous sodium silicate (40% active) supplied by Chemical Products Corporation of Cartersville, Ga., marketed by the trade name of ChemSilate.
- the clay was dried at 150° C.
- PSD extremely narrow particle size distribution
- Table 1 provides comparative data.
- the pigment used in the coating formulation was a mixture of 75% fine #1 coating kaolin clay and 25% Carbital 90, a calcium carbonate product having a particle size distribution such that 90% thereof by weight are less than 2 microns E.S.D., supplied by Atlantic Carbonates of Baltimore, Md.
- column B 60% of #1 coating clay was used, 10% of Carbital 90 and 30% of pigment W prepared by treatment of a kaolin clay having a PSD of 96% less than 2 micrometers E.S.D., with silicon tetrachloride followed by ammonia (see the aforementioned PCT application).
- pigment W was replaced by pigment SiXC which designates the pigment according to the invention prepared as just described above.
- improvement in surface coverage paper gloss and print gloss
- FIGS. 2 and 3 further illustrate the paper gloss and printability of the coated paper, column C.
- FIG. 4 further illustrates that the use of Pigment SiXC also provides an open coating to improve ink receptivity, as measured by the K and N ink receptivity test.
- Example II The general preparation of the feed clay and chemical treatments were similar to those described in Example I, except that the feed clays were reacted with varying amounts of the silicate solution, i.e., from 0.6 weight % to 12.5 weight %.
- the particle size distribution analysis indicated that aggregation occurs even when using 0.6 weight % silicate solution; however, the product with the most preferred properties was obtained when a 2.5 weight % silicate solution was used.
- a series of clays was prepared by treating a feed clay, prepared as described in Example I, with 2.5% by weight of sodium silicate solutions of varying SiO 2 /Na 2 O ratios, which ranged from 1.25 to 3.8.
- the above clays were pulverized and dried to 0.8% moisture. These clays were exposed to moist hydrochloric gas to form and polymerize silicic acid. The reaction was allowed to proceed for about five to fifteen minutes, until the pH reached 6 to 6.5. The excess gas was vented and the product was either dried in air or at 150° C. for fifteen minutes.
- Example 2 The general preparation of the feed clay was similar to that described in Example I.
- the amount of silicate solution used was identical to that used in Example I.
- Pulverized clay was this time treated with anhydrous HCl gas.
- the pH of the product was 2.5.
- the light scatter results of filled hand sheets indicated that the use of anhydrous HCl gas provides a pigment of higher light scatter coefficient, thus the preferred mode of silicate condensation is use of anhydrous HCl gas, see Table 2.
- Example II The initial steps of feed clay preparation, i.e. degritting, refining and size classification, were similar to Example I. However, the classified clay was first dosed with 2.5% by weight, based on dry clay, of the sodium silicate solution prior to spray drying. The dry clay was then pulverized and reacted with dry HCl gas as described in Example IV. This process provides aggregated clay of similar opacifying properties as obtained with the dry addition process. Table 3, however, shows that the final product may be contaminated with a higher than desirable amount of 325 mesh residue.
- the rate and extent of monosilicic acid polymerization depends on the construction and the mobility of the molecules. In the liquid state, the mobility of such species would be several orders of magnitude higher than in the dry state. Thus, the amount of moisture available on the claiy surface would have a significant effect on the final properties of silicate aggregated clays.
- a series of samples was prepared by taking a stock sample of the feed clay to the HCl treating step, as prepared in Example I, and blending it with the required amount of water to achieve moisture levels of 0.05, 2.3, 4.3, 8.5 and 15.3. These clays were then rapidly exposed to dry HCl gas, as in Example IV. The final product clearly shows reduction in opacifying power of aggregated clay at higher moisture, see FIG. 5.
- the particle size distribution and pore void volume measurements indicated that aggregation is accomplished with a very small amount of silicate; the preferred amount is 2.5 weight % of a 40% active sodium silicate solution.
- This invention describes the method of clay particle aggregation by a chemical method. Such reaction would depend not only on the size fraction of the feed clay but also on the shape of the feed clay.
- the shape factor of the feed clays was varied by mixing beneficiated and classified slurries of a fine but chunky clay, with coarse, highly laminated clay, to that the ratios of fine clay to laminated clay were in the range of 0.0 to 1.0.
- the blend slurry was followed by spray drying and pulverizaion.
- These feeds were then reacted with 2.5 weight % sodium silicate solution (40% active) as described in Example I.
- the clays were then reacted with anhydrous HCl gas as in Example IV.
- the pore void volume increases with the amount of coarse, platey clay (Alpha-plate) but opacifying power, as determined by light scatter, increases with fine feed clay, see FIG. 6.
- the general preparation of feed clay was similar to Example I, except that the redispersed clay was treated with 4.4 weight % calcium chloride dihydrate salt (supplied by Aldrich Chemical Co.) prior to spray drying. Calcium chloride was added as a 2.0M solution. After spray drying and pulverization, this clay was blended with 2.5 weight % sodium silicate solution (40% active). The resulting clay was dried and pulverized. The moisture of the clay was 0.85% by weight. The dry, pulverized clay was exposed to anhydrous hydrochloric acid according to Example IV. The light scatter results show 5% improvement over feed clay without calcium chloride.
- Example II The general preparation of the feed clay was similar to that described in Example I, except that the redispersed clay was treated with 3% ground calciumcarbonate prior to spray drying.
- the pulverization and chemical treatment following spray drying was similar to that in Example IX.
- the product is an aggregated clay with an extremely narrow particle size distribution.
- the pH of the product was 2.5.
- the light scatter of this product was 10 units higher than the product of a feed clay containing no ground calcium carbonate.
- Example X The chemicals and process used were similar to Example X, except that this time 3% ground calcium carbonate was added after spray drying of the feed clay.
- the light scatter of this product is similar to that where calcium carbonate was added prior to spray drying of the feed clay.
- Example X The general feed clay preparation was similar to Example X.
- the pulverization and chemical treatment following spray drying were similar to Example I where moist hydrochloric acid gas was used.
- the particle size distribution of the product was similar to the product described in Example X.
- the feed clay and the process of aggregation were similar to Example IV, except that this time residual hydrochloric acid was neutralized with anhydrous ammonia so that the final pH of the product would be 7.0 to 7.5.
- the pore void volume measurement indicated improved aggregation upon neutralization of hydrochloric acid with gaseous ammonia.
- Example XI The general procedure for feed clay preparation was similar to Example XI, except this time 2.22 weight % calcium hydroxide powder (supplied by J. T. Baker Chemical Co.) was added to the spray dried feed clay.
- the aggregation process with sodium silicate and hydrochloric acid was identical to that in Example XI.
- the light scatter of this prduct was similar to the product of Example IX.
- Example X The general feed clay preparation and pulverization were similar to those described in Example X.
- the chemical treatment leads to an improvement in pore void volume from 0.22 cm 3 /g to 0.41 cm 3 /g.
- the feed clay was prepared by a dry, air classification method.
- the crude clay was dried to moisture less than 0.5% by weight.
- the dried clay was pulverized and air classified to 92-94% less than 2 micrometer.
- the subsequent chemical aggregation treatment was similar to that in Example IV.
- Particle size distribution indicated aggregation of fine particles to provide a product of narrow particle size distribution with increased pore void volume.
Abstract
Description
TABLE 1 ______________________________________ Properties of Paper Coated with Silicate Aggregated Kaolinite Pigments A 75% B C #1Clay 60% #1Clay 60% #1 Clay 25% 10% Carbital 90 10% Carbital 90 Properties Carbital 90 30% Pigment W 30% Pigment SiXC ______________________________________ Brightness 71.3 71.9 71.3 Opacity 90.7 91.2 90.6 Gloss 59.0 64.5 64.0 Print Gloss 75.0 76.6 77.9 Litho P. 61.6 68.7 64.5 Gloss Print 1.78 1.72 1.73 Density Litho P. 1.33 1.38 1.30 Density P. Density 0.75 0.80 0.75 Ratio K & N 18.6 23.2 20.4 ______________________________________
TABLE 2 ______________________________________ Effect of Dry vs. Moist Hydrochloric Acid On Normalized Light Scatter of Pigment SiXC Normalized Light Scatter Pigment at 10% Filler Loading ______________________________________ Feed Clay 485 Pigment SiXC Using Moist HCl 521 Pigment SiXC Using Dry HCl 535 ______________________________________
TABLE 3 ______________________________________ The Point of Sodium Silicate Solution Addition and Its Effect on Light Scatter and 325 Mesh Residue Normalized Percent Light Scatter 325 Mesh Pigment at 10% Filler Loading Residue ______________________________________Feed Clay 490 <0.001 Pigment SiXC 521 0.5 Silicate Solution Added Before Spray Drying of Feed Clay Pigment SiXC 526 0.05 Silicate Solution Added After Spray Drying of Feed Clay ______________________________________
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Priority Applications (1)
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US07/149,638 US4816074A (en) | 1985-07-12 | 1988-01-28 | Kaolinite aggregation using sodium silicate |
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
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US75447585A | 1985-07-12 | 1985-07-12 | |
US80284385A | 1985-11-27 | 1985-11-27 | |
US06/918,632 US4820554A (en) | 1985-11-27 | 1986-10-14 | Coated paper and process |
US07/149,638 US4816074A (en) | 1985-07-12 | 1988-01-28 | Kaolinite aggregation using sodium silicate |
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US75447585A Continuation-In-Part | 1985-07-12 | 1985-07-12 | |
US80284385A Continuation-In-Part | 1985-07-12 | 1985-11-27 | |
US06/918,632 Continuation-In-Part US4820554A (en) | 1985-07-12 | 1986-10-14 | Coated paper and process |
US07/001,889 Continuation-In-Part US4826536A (en) | 1986-10-14 | 1987-01-09 | Structured kaolin pigments |
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US07/149,638 Expired - Fee Related US4816074A (en) | 1985-07-12 | 1988-01-28 | Kaolinite aggregation using sodium silicate |
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Cited By (24)
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US4971629A (en) * | 1989-10-04 | 1990-11-20 | Ecc America Inc. | Method of preparing aggregated pigments from clays |
US4976786A (en) * | 1989-10-04 | 1990-12-11 | Ecc America Inc. | Method for forming aggregated kaolin pigment |
WO1991005745A1 (en) * | 1989-10-12 | 1991-05-02 | Industrial Progress, Inc. | Process for making structural aggregate pigments |
US5022924A (en) * | 1990-02-21 | 1991-06-11 | Ecc America Inc. | Method for reducing the abrasion of calcined clay |
US5082887A (en) * | 1989-12-29 | 1992-01-21 | Ecc American Inc. | Aggregated composite mineral pigments |
GB2251254A (en) * | 1990-12-04 | 1992-07-01 | Ecc Int Ltd | Inorganic material slurry |
US5151124A (en) * | 1990-06-04 | 1992-09-29 | Ecc America Inc. | Method for forming aggregated kaolin pigment |
US5203918A (en) * | 1990-06-04 | 1993-04-20 | Ecc America Inc. | Method for forming aggregated kaolin pigment |
US5219660A (en) * | 1987-06-01 | 1993-06-15 | Wason Satish K | Precipitated encapsulated paper pigments and methods |
US5312485A (en) * | 1988-08-05 | 1994-05-17 | J. M. Huber Corporation | Precipitated encapsulated paper pigments and methods |
US5352287A (en) * | 1988-08-05 | 1994-10-04 | J. M. Huber Corporation | Precipitated encapsulated paper pigments and methods |
WO1996006807A1 (en) * | 1994-08-26 | 1996-03-07 | Thiele Kaolin Company | Opacifying kaolin clay pigments having improved rheology and process for the manufacture thereof |
US5584925A (en) * | 1995-06-26 | 1996-12-17 | Thiele Kaolin Company | Chemically aggregated kaolin clay pigment and process for making the same by phosphate bonding |
US5731034A (en) * | 1990-12-04 | 1998-03-24 | Ecc International Limited | Method of coating paper |
US5747110A (en) * | 1992-01-14 | 1998-05-05 | Bowater Packaging Limited | Porous webs |
US5843861A (en) * | 1996-12-23 | 1998-12-01 | Thiele Kaolin Company | Process for the synthesis of kaolin clays having varying morphological properties |
WO2000031190A1 (en) * | 1998-11-19 | 2000-06-02 | Engelhard Corporation | Low sheen opacifying pigments and manufacture thereof by calcination of kaolin clay |
US6270566B1 (en) | 1989-05-10 | 2001-08-07 | Bayer Ag | Process for colouring building materials |
EP1132520A1 (en) * | 2000-03-10 | 2001-09-12 | J.M. Huber Corporation | A paper or paper board coating composition containing a structured clay pigment |
US20050126730A1 (en) * | 2000-08-17 | 2005-06-16 | Marielle Lorusso | Kaolin products and their use |
US20070104859A1 (en) * | 2005-05-10 | 2007-05-10 | Michael Featherby | Coating for environmental protection and indication |
WO2009112635A1 (en) * | 2008-03-14 | 2009-09-17 | Kautar Oy | Reinforced porous fibre product |
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US20130199745A1 (en) * | 2010-11-05 | 2013-08-08 | Nordkalk Oy Ab | Process for manufacturing paper and board |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE1176466B (en) * | 1958-01-02 | 1964-08-20 | Bayer Ag | Paper filler |
US4299807A (en) * | 1978-04-17 | 1981-11-10 | Yara Engineering Corporation | Methods of producing kaolin pigments |
US4419228A (en) * | 1980-08-25 | 1983-12-06 | Anglo-American Clays Corporation | Process for producing high brightness clays utilizing magnetic beneficiation and calcining |
US4650521A (en) * | 1983-07-14 | 1987-03-17 | Georgia Kaolin Company, Inc. | Processing of kaolinitic clays at high solids under acidic conditions |
US4738726A (en) * | 1985-05-06 | 1988-04-19 | Engelhard Corporation | Treatment of clays with cationic polymers to prepare high bulking pigments |
-
1988
- 1988-01-28 US US07/149,638 patent/US4816074A/en not_active Expired - Fee Related
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE1176466B (en) * | 1958-01-02 | 1964-08-20 | Bayer Ag | Paper filler |
US4299807A (en) * | 1978-04-17 | 1981-11-10 | Yara Engineering Corporation | Methods of producing kaolin pigments |
US4419228A (en) * | 1980-08-25 | 1983-12-06 | Anglo-American Clays Corporation | Process for producing high brightness clays utilizing magnetic beneficiation and calcining |
US4650521A (en) * | 1983-07-14 | 1987-03-17 | Georgia Kaolin Company, Inc. | Processing of kaolinitic clays at high solids under acidic conditions |
US4738726A (en) * | 1985-05-06 | 1988-04-19 | Engelhard Corporation | Treatment of clays with cationic polymers to prepare high bulking pigments |
Cited By (35)
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US5116418A (en) * | 1984-12-03 | 1992-05-26 | Industrial Progress Incorporated | Process for making structural aggregate pigments |
US5219660A (en) * | 1987-06-01 | 1993-06-15 | Wason Satish K | Precipitated encapsulated paper pigments and methods |
US5352287A (en) * | 1988-08-05 | 1994-10-04 | J. M. Huber Corporation | Precipitated encapsulated paper pigments and methods |
US5312485A (en) * | 1988-08-05 | 1994-05-17 | J. M. Huber Corporation | Precipitated encapsulated paper pigments and methods |
US6270566B1 (en) | 1989-05-10 | 2001-08-07 | Bayer Ag | Process for colouring building materials |
US4976786A (en) * | 1989-10-04 | 1990-12-11 | Ecc America Inc. | Method for forming aggregated kaolin pigment |
US4971629A (en) * | 1989-10-04 | 1990-11-20 | Ecc America Inc. | Method of preparing aggregated pigments from clays |
WO1991005745A1 (en) * | 1989-10-12 | 1991-05-02 | Industrial Progress, Inc. | Process for making structural aggregate pigments |
US5082887A (en) * | 1989-12-29 | 1992-01-21 | Ecc American Inc. | Aggregated composite mineral pigments |
US5022924A (en) * | 1990-02-21 | 1991-06-11 | Ecc America Inc. | Method for reducing the abrasion of calcined clay |
US5151124A (en) * | 1990-06-04 | 1992-09-29 | Ecc America Inc. | Method for forming aggregated kaolin pigment |
US5203918A (en) * | 1990-06-04 | 1993-04-20 | Ecc America Inc. | Method for forming aggregated kaolin pigment |
US5731034A (en) * | 1990-12-04 | 1998-03-24 | Ecc International Limited | Method of coating paper |
GB2251254A (en) * | 1990-12-04 | 1992-07-01 | Ecc Int Ltd | Inorganic material slurry |
GB2251254B (en) * | 1990-12-04 | 1994-06-29 | Ecc Int Ltd | Calcium carbonate slurry |
US5747110A (en) * | 1992-01-14 | 1998-05-05 | Bowater Packaging Limited | Porous webs |
US5584924A (en) * | 1994-08-26 | 1996-12-17 | Thiele Kaolin Company | Opacifying kaolin clay pigments having improved rheology and process for the manufacture thereof |
WO1996006807A1 (en) * | 1994-08-26 | 1996-03-07 | Thiele Kaolin Company | Opacifying kaolin clay pigments having improved rheology and process for the manufacture thereof |
US5584925A (en) * | 1995-06-26 | 1996-12-17 | Thiele Kaolin Company | Chemically aggregated kaolin clay pigment and process for making the same by phosphate bonding |
US5843861A (en) * | 1996-12-23 | 1998-12-01 | Thiele Kaolin Company | Process for the synthesis of kaolin clays having varying morphological properties |
US6402827B1 (en) | 1998-09-01 | 2002-06-11 | J.M. Huber Corporation | Paper or paper board coating composition containing a structured clay pigment |
US6346145B1 (en) | 1998-11-19 | 2002-02-12 | Engelhard Corporation | Paints containing low sheen opacifying pigments obtained by flux calcination of kaolin clay |
US6136086A (en) * | 1998-11-19 | 2000-10-24 | Englehard Corporation | Low sheen opacifying pigments and manufacture thereof by calcination of kaolin clay |
WO2000031190A1 (en) * | 1998-11-19 | 2000-06-02 | Engelhard Corporation | Low sheen opacifying pigments and manufacture thereof by calcination of kaolin clay |
EP1132520A1 (en) * | 2000-03-10 | 2001-09-12 | J.M. Huber Corporation | A paper or paper board coating composition containing a structured clay pigment |
US20050126730A1 (en) * | 2000-08-17 | 2005-06-16 | Marielle Lorusso | Kaolin products and their use |
US7413601B2 (en) * | 2000-08-17 | 2008-08-19 | Imerys Pigments, Inc. | Kaolin products and their use |
US20070104859A1 (en) * | 2005-05-10 | 2007-05-10 | Michael Featherby | Coating for environmental protection and indication |
WO2009112635A1 (en) * | 2008-03-14 | 2009-09-17 | Kautar Oy | Reinforced porous fibre product |
US20110061827A1 (en) * | 2008-03-14 | 2011-03-17 | Kautar Oy | Reinforced porous fibre product |
US8354003B2 (en) | 2008-03-14 | 2013-01-15 | Nordkalk Oy Ab | Reinforced porous fibre product |
RU2494184C2 (en) * | 2008-03-14 | 2013-09-27 | Нордкалк Ой Эйби | Porous fibrous product with increased durability |
EP2486189A1 (en) * | 2009-10-09 | 2012-08-15 | Stora Enso Oyj | A process for the production of a substrate comprising silica pigments which is formed on the surface of the substrate |
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US20130199745A1 (en) * | 2010-11-05 | 2013-08-08 | Nordkalk Oy Ab | Process for manufacturing paper and board |
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